<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>双飞翼</title>
<link rel="stylesheet" type="text/css" href="style.css">
</head>


<body>
	<div class="header">头部</div>
	<div class="content">
		<div class="col-main"><div class="main">我是主列</div></div>
		<div class="col-sub">我是子列</div>
     	<div class="col-extra">我是附加列</div>
    </div>
    <div class="footer">尾部</div>
</body>
</html>
